embedded gaia hotspot integration

hi,I want to hotspot integration ( hotspot customer's private software) so I choose hotspot interface after that I did radius configuration and I did Browser-Based Authentication , also I redirect to custom hotspot portal on "portal address tab" but I get following error , but when I dont choose portal address tab, it redirecte to checkpoint portal( default captive portal) it is running , but when I want to redirect to custom portal it is not running. also I added error screenshot